Method of producing thin resin films

ABSTRACT

A method for manufacturing a resin thin film of the present invention includes supplying a liquid resin material and a gas to a two-fluid nozzle by pressure; ejecting the resin material in the form of atomized particles toward a heating member by the two-fluid nozzle, thereby adhering the resin material to the heating member; or mixing a liquid resin material with a gas; ejecting the resin material in form of atomized particles toward a heating member that is provided under reduced pressure, thereby adhering the resin material to the heating member; and evaporating the resin material on the heating member to obtain the evaporated resin material. Thus, the present invention can provide a resin thin film having a uniform thickness stably with simple means at a low cost. The resin thin film obtained by the present invention can be used in a wide range, for example a magnetic recording medium such as a magnetic tape, a wrapping material, and an electronic component.

TECHNICAL FIELD

The present invention relates to a method for manufacturing a resin thinfilm, in particular, a method for forming a resin thin film on asupporting base by evaporating a resin material so that the resinmaterial is deposited on a surface of the supporting base.

BACKGROUND ART

Thin films play an important part in a wide range of aspects of currentsociety and are utilized in a variety of areas in our daily life such aswrapping papers, magnetic tapes, capacitors, semiconductors or the like.The basic trends of technology including high performance andminiaturization in recent years cannot be discussed without referring tosuch thin films. At the same time, various methods for forming a thinfilm have been under development to satisfy industrial demands. Forexample, continuous winding vacuum evaporation, which is advantageous tohigh-speed mass production, has been performed to form the thin filmsfor use in wrapping papers, magnetic tapes, capacitors or the like. Inthis case, a thin film having desired characteristics can be formed byselecting an evaporation material and a substrate material to meet thepurpose of the thin film to be formed and introducing a reactive gas ina vacuum chamber, if necessary, or forming the thin film while applyingan electric potential to the substrate.

A method for forming a resin thin film by coating a supporting base witha resin material that is diluted with a solvent is known as a method forobtaining a resin thin film. Reverse coating or die coating is usedindustrially, and generally the material is dried and cured aftercoating. The thickness of coating by a common coating technique isseveral μm or more immediately after coating. Therefore, the material isrequired to be diluted with a solvent to form a very thin resin film.Nevertheless, the lower limit of the thickness of the resin thin filmformed by these methods is often around 1 μm, although it may be varieddepending on the material used. It is often difficult to obtain athickness less than 1 μm. Furthermore, the solvent dilution is notpreferable, because the dilution with a solvent causes defects readilyin a coating film after drying due to the evaporation of the solvent, aswell as in view of environmental protection. Therefore, a method forforming a resin thin film without the solvent dilution and a method bywhich a very thin resin film can be obtained stably are in demand.

As a method to solve this problem, a method for forming a resin thinfilm in a vacuum has been proposed. For example, EP 0 808 667 disclosesthe following method. A resin material is supplied to a heating memberso as to be heated and evaporated in a vacuum. Then, the resin materialis deposited on a moving supporting base so that a resin thin film isformed on the supporting base continuously. This method permits theresin thin film to be formed without void defects and the solventdilution to be eliminated.

However, in the method disclosed in EP 0 808 667, the amount of theresin material evaporated is not stable, so that the obtained resin thinfilm cannot have a uniform thickness. In addition, the properties of theobtained resin thin film are not stable, or a resin thin film havingdesired properties cannot be obtained. In particular, the demand for thecharacteristics of the resin thin film that is to be used in electroniccomponents have become increasingly high. The problems as describedabove reduce the yield of the products and increase the cost.

The inventors of the present invention studied to solve the problems inthe conventional method for manufacturing a thin film. As a result, theyfound out that these problems were caused by the manner in which theresin material is supplied to a heating member.

More specifically, conventionally, the resin material is supplied to aheating member after the resin material is atomized with an ultrasonictransducer, a spray nozzle, or a mechanical atomizer.

However, in atomization with an ultrasonic transducer, it is difficultto atomize the resin material stably for a long time. Moreover, theresin material is heated by a mechanical external force applied to theresin material during the process of atomization, so that the nature ofthe resin material may be changed or the resin material may besolidified before being atomized. When the nature of the resin materialhas been changed, not only is the amount of the resin materialevaporated not stabilized, but also a resin thin film having desiredproperties cannot be obtained. Furthermore, expensive equipment isrequired so that a cost-efficient resin thin film cannot be obtained.

Atomization with a spray nozzle is not suitable for a resin materialhaving a large viscosity, so that the range of usable resin materials islimited. Moreover, since the particle size of the atomized resinmaterial is relatively large, it is difficult to atomize the resinmaterial stably when the amount of the resin material supplied is small,Therefore, it is difficult to form a resin thin film having a smallthickness stably.

Furthermore, in atomization with a mechanical atomizer, an externalforce applied to the resin material for atomization is large, andtherefore the resin material is heated. As a result, the nature of theresin material is changed or the resin material is solidified beforebeing atomized. Furthermore, as in the case of the spray nozzle, sincethe particle size of the obtained resin material is relatively large, itis difficult to form a resin thin film having a small thickness stably.

DISCLOSURE OF INVENTION

It is an object of the present invention to provide a method formanufacturing a resin thin film that can solve the above problems andmanufacture a resin thin film having a uniform thickness stably withsimple apparatus at a low cost, by using a new method for supplying aresin material that can be substituted for the conventional supplymethod.

The present invention can have the following embodiments to achieve theabove object.

A method for manufacturing a resin thin film according to a firstembodiment of the present invention is a method for manufacturing aresin thin film by depositing an evaporated resin material on a surfaceof a supporting base. The method includes supplying a liquid resinmaterial and a gas to a two-fluid nozzle by pressure; ejecting the resinmaterial in the form of atomized particles toward a heating member bythe two-fluid nozzle, thereby adhering the resin material to the heatingmember; and evaporating the resin material on the heating member toobtain the evaporated resin material.

A method for manufacturing a resin thin film according to a secondembodiment of the present invention is a method for manufacturing aresin thin film by depositing an evaporated resin material on a surfaceof a supporting base. The method includes mixing a liquid resin materialwith a gas; ejecting the resin material in the form of atomizedparticles toward a heating member that is provided under a reducedpressure, thereby adhering the resin material to the heating member; andevaporating the resin material on the heating member to obtain theevaporated resin material.

According to the first and second embodiments of the present invention,the liquid resin material is ejected to a heating member by a two fluidnozzle or is ejected to a heating member that is provided under areduced pressure after being mixed with a gas, so that the resinmaterial in the form of atomized particles adheres to the heatingmember. Therefore, a mechanical external force that can affect the resinmaterial in the process of atomization can be small, and therefore heatgeneration can be suppressed. As a result, the nature of the resinmaterial can be prevented from changing, so that a resin thin filmhaving desired properties can be obtained. Moreover, since the heatgeneration is small, the resin material is not solidified before beingatomized. As a result, a resin thin film having a uniform thickness canbe obtained stably. In addition, since the size of the obtained atomizedparticles is small, the amount of the resin material adhered to theheating member can be stabilized. As a result, the present invention canbe used to manufacture a resin thin film having a very small thickness.In addition, since the range of usable resin materials is wide, a widerange of resin thin films having required properties can be manufacturedby changing the resin material as appropriate. In addition, since theequipment for atomization is simple, a resin thin film can bemanufactured at low cost.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional drawing schematically showing an internalstructure of an example of an apparatus used in a method formanufacturing a resin thin film according to Embodiment 1 of the presentinvention.

FIG. 2 is a cross-sectional drawing schematically showing the structureof an example of a two-fluid nozzle according to Embodiment 1 of thepresent invention.

FIG. 3 is a graph showing an example of relationship between the flowrate of a gas, the average particle diameter of a resin sprayed from thetwo-fluid nozzle, the pressure in an apparatus for forming a resin thinfilm, the film-forming rate, and the number of defects contained in theresin thin film, when the two-fluid nozzle of Embodiment 1 of thepresent invention is used.

FIG. 4 is a cross-sectional drawing schematically showing an internalstructure of an example of an apparatus used in a method formanufacturing a resin thin film according to Embodiment 2 of the presentinvention.

FIG. 5 is a cross-sectional drawing schematically showing an internalstructure of an example of an apparatus for manufacturing a layeredproduct including resin thin films and metal thin films according toEmbodiment 3 of the present invention.

FIG. 6 is a front view of an apparatus for applying a patterningmaterial used in the production apparatus of FIG. 5, when viewed fromthe side of a can roller.

FIG. 7 is a perspective view schematically showing an example of astructure of a layered base element including resin thin films and metalthin films obtained by Embodiment 3 of the present invention.

FIG. 8 is a perspective view schematically showing an example of astructure of a chip capacitor obtained by Embodiment 3 of the presentinvention.

FIG. 9 is a cross-sectional drawing schematically showing an internalstructure of the ultrasonic atomizer used in Comparative Example 1.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described with reference tothe accompanying drawings more specifically.

Embodiment 1

FIG. 1 is a cross-sectional drawing schematically showing an internalstructure of an example of an apparatus for manufacturing a resin thinfilm for performing the present invention.

A belt-shaped supporting base 110 on which a resin thin film is formedis unwound from an unwinding roll 121 that rotates in a rotationdirection 122, and passes along a guide roll 123, travels along acylindrical can roller 111 that rotates in a rotation direction 112.Then, the supporting base 110 passes along a guide roll 127 and wound bya winding roll 125 that rotates in a rotation direction 126. As thebelt-shaped supporting base 110, a long resin film on which an Alevaporated film is formed can be used. The can roller 111 is cooled to,preferably —20° C. to 40° C., more preferably, —10° C. to 10° C.

The main components of the apparatus 100 for manufacturing a resin thinfilm are housed in a vacuum container 101. The vacuum container ispartitioned substantially into two compartments by partition walls 130and 131. The upper compartment 150 (a second compartment) including theunwinding roll 121 and the winding roll 125 is maintained at about5×10⁻⁴ Torr by a vacuum pump 151. The lower compartment 250 (a firstcompartment) including an apparatus 200 for forming a resin thin film(hereinafter, referred to as “resin thin film forming apparatus”) ismaintained at about 2×10⁻⁴ Torr by another vacuum pump 251. Thus, thepressure in the lower compartment 250 (the first compartment) is lowerthan that of the upper compartment 150 (the second compartment). Thisdesign prevents the vapor of the resin from entering the uppercompartment. As a result, the amount of the resin material adhered tothe transporting system of the supporting base can be reduced, so thatthe frequency of maintenance can be small.

A resin material to be formed into a resin thin film on the supportingbase 110 is heated in the resin thin film forming apparatus 200 providedunder the can roller 111 so as to be evaporated. Since the pressure inthe lower compartment 250 that is outside the resin thin film formingapparatus 200 is lower than that in the resin thin film formingapparatus 200, the evaporated resin material is released through anopening 209 provided in an opening plate 208. Since the opening 209 isprovided opposed to the circumferential surface of the can roller 111,the released resin material is deposited on the travelling supportingbase 110, and solidified so as to form a resin thin film.

The formed resin thin film is cured to a desired curing degree by anultraviolet ray irradiation device 140, if necessary, and then wound bythe winding roll 125.

The resin material is evaporated in the following manner.

A liquid resin material is supplied to a two-fluid nozzle 230 in theresin thin film forming apparatus 200 through a tube 241 for supplying aresin material (hereinafter, referred to as “resin material supplytube”) at a predetermined flow rate adjusted by a valve 242 foradjusting a flow rate. A gas is supplied to the two-fluid nozzle 230through a tube 243 for supplying a gas (hereinafter, referred to as “gassupply tube”) at a predetermined gas flow rate adjusted by a valve 244for adjusting a gas flow rate. The resin material is ejected in the formof atomized particles together with the gas from an outlet of thetwo-fluid nozzle toward a heating roll 204, which rotates in thedirection shown by the arrow. The structure of the two-fluid nozzle 230is not limited to a particular structure, and can be selected asappropriate, depending on the properties of the resin material used(e.g., viscosity), the amount of the resin material ejected, or theshape of the heating member.

FIG. 2 is a cross-sectional drawing schematically showing the structureof an example of the two-fluid nozzle 230 that can be used in thisembodiment.

The two-fluid nozzle in FIG. 2 includes an outer cylinder 231, an innercylinder 232 engaged in the outer cylinder, and an O-ring 233 forsealing the outer cylinder 231 and the inner cylinder 232. A port 234for supplying a resin material is formed on one end face of the innertube 232, and the resin material supply tube 241 is connected thereto soas to supply the liquid resin material. On the other hand, a port 235for supplying a gas is formed on the side of the outer cylinder 231, andthe gas supply tube 243 is connected thereto so as to introduce a gas.Thus, the resin material is atomized by the gas and ejected from anoutlet 236. For simplification, in FIG. 2, the shape of the outlets ofthe resin and the gas is a round shape. However, in the case where theresin is sprayed to the heating roll 204, as shown in FIG. 1, it isdesirable that the shape of resin being sprayed is a fan-shape containedin a plane perpendicular to the sheet of the FIG. 1. This is becauseuniform attachment of the resin to the heating roll 204 in thelongitudinal direction (the direction perpendicular to the sheet ofFIG. 1) results in more stable evaporation of the resin. For thisreason, it is desirable that the resin outlet and the gas outlet of thetwo-fluid nozzle are parallel slits. Moreover, the two-fluid nozzle isarranged so that these slits face the heating roll 204 in parallel tothe longitudinal direction of the heating roll 204.

A preferable gas to be used is an inert gas, for example a gascontaining at least one selected from the group consisting of nitrogen,oxygen, argon, helium and neon. Among these, nitrogen is mostpreferable, because it is inexpensive and it makes it easy to adjust thecuring degree of the resin thin film, when oxygen is contained.

The pressure and the flow rate of the gas used are required to beadjusted as appropriate, depending on the viscosity of the resinmaterial used or the amount of the resin material supplied. FIG. 3 is agraph showing an example of the dependence of the average particlediameter of the resin sprayed from the two-fluid nozzle, the pressure inthe resin thin film forming apparatus 200, the film-forming rate, andthe number of defects contained in the resin thin film with respect tothe gas flow rate, when the same two-fluid nozzle is used and the flowrate (5 cc/min) and the pressure of the resin are constant.

The average particle diameter of the resin sprayed from the two-fluidnozzle decreases as the gas flow rate increases. However, the extent ofthe decrease is sharp in a region where the gas flow rate is small, andthereafter the extent of the decrease gradually becomes smaller as thegas flow rate increases.

The pressure in the resin thin film forming apparatus 200 with respectto the gas flow rate increases significantly in a region where theaverage particle diameter of the sprayed resin drops sharply. This isbecause the surface area of the sprayed resin becomes larger as theaverage particle diameter becomes smaller, so that the evaporationefficiency becomes high. However, in a region where the gas flow rate issubstantially the same as that of the resin (5 cc/min) or more, thepressure in the resin thin film forming apparatus 200 tends to besaturated, and thereafter increases substantially in proportion to thegas flow rate.

Corresponding thereto, the film forming rate increases in a region ofthe gas flow rate where the pressure in the resin thin film formingapparatus 200 increases sharply. When the average particle diameter ofthe introduced resin becomes a certain value or less (40 μm or less inFIG. 3), 100% of the introduced resin is evaporated, so that the filmforming rate is substantially constant.

On the other hand, the number of defects contained in the resin thinfilm decreases sharply as the average particle diameter of the sprayedresin decreases. The reason for this is as follows. When the averageparticle diameter is large, the resin cannot adhere uniformly onto theheating roll 204. In addition, the thickness of the resin materialbecomes large, so that the convection in the liquid film is notsufficiently effected so that the entire liquid film cannot be heateduniformly. Consequently, bumping of the resin material occurs (herein,“bumping” indicates the phenomenon where the resin material is heatedrapidly so as to be boiled so that liquid drops of the resin materialare scattered), thus resulting in a large number of large particlesreaching the supporting base 110. However, when the gas flow rateincreases further, the number of defects in the film becomes very small,and thereafter increases again. This is because although less bumping ofthe resin material occurs, the gas is taken into the film and causesdefects.

As seen from FIG. 3, when the resin flow rate is constant, an optimalregion of the gas flow rate exists in view of the film forming rate andthe number of defects in the film. FIG. 3 shows the case of the resinhaving a viscosity of 50 to 150 CPS. In this case, when the gas isintroduced to the two-fluid nozzle at a flow rate of 40 to 100% of theresin flow rate, a resin thin film having good productivity and goodquality can be obtained. In general, when the viscosity of the resin ishigh, it is necessary to increase the gas flow rate relatively. In thehighest case, 200% of the resin flow rate may be required as the gasflow rate. On the other hand, in the case where the viscosity of theresin is less than 50 CPS, the gas flow rate can be relatively small,and in the lowest case, the gas flow rate can be about 10% of the resinflow rate.

The resin material ejected from the two-fluid nozzle 230 in the form ofatomized particles adheres to an area of some extent on the heating roll204, which rotates in the direction shown by the arrow in FIG. 1. Theadhered resin material in the form of a large number of fine liquiddroplets evaporates on the surface of the heating roll 204.Alternatively, the adhered resin material spreads over the surface ofthe heating roll 204 to form a thin liquid film of the fine liquiddroplets being linked, and a part thereof evaporates. In the presentinvention, the resin material is adhered to the heating roll 204 in theform of very fine atomized particles having a relatively uniformparticle diameter. This embodiment allows the formed liquid film to havea very small and uniform thickness. As a result, the amount of the resinmaterial evaporated can be stabilized. When the particle diameter of theparticles adhered to the heating roll 204 is large, or when the particlediameter is not uniform, the thickness of the formed liquid film also islarge and non-uniform. Therefore, the convection in the liquid film isnot sufficiently effected so that the entire liquid film is notuniformly heated. Consequently, only the resin material in the veryvicinity of the surface of the heating roll 204 is heated rapidly, andthe resin material in that portion is cured by the heat. As a result, itis unlikely to obtain a resin thin film having a uniform thickness.Moreover, the bumping of the resin material occurs so that a largenumber of large particles are scattered. Then, large protrusions or thelike are formed on the surface of the formed resin thin film, thusdeteriorating the smoothness of the surface and increasing defects inthe resin thin film.

It is desirable that the resin material adhered to the heating roll 204has evaporated during one rotation of the heating roll 204, but cannotevaporate in some cases, depending on various conditions such as theamount of the resin material supplied or the type of the resin material.In such a case, as shown in FIG. 1, it is desirable to provide a firstheating plate 205 a and a second heating plate 205 b under the heatingroll 204. In this design, the resin material that has not beenevaporated on the heating roll 204 and reached the lowest portion dropsonto the first heating plate 205 a and moves thereon, and further dropsonto the second heating plate 205 b. This resin material spreads in theform of a liquid film while moving on these heating plates, so that apart thereof evaporates.

As described above, when the liquid resin material is allowed to movealong the heating member, the resin material can be heated while beingspread in the form of a thin film, so that the resin material can beheated uniformly. Thus, the amount of the resin material evaporated canbe increased and stabilized. If the resin material is allowed to stay ina limited area and heated without allowing to move, the convection inthe resin material is poor and the resin material is not heateduniformly, so that the resin material in the vicinity of the surface ofthe heating plates is thermally cured or the bumping occurs, so that alarge number of large particles are scattered. As a result, not only isthe amount of the resin material evaporated small, but also thenon-uniformity of the thickness of the formed resin thin film becomesworse, and the smoothness of the surface deteriorates due to the largeprotrusions.

The resin material that has not been evaporated ultimately drops in acooling cup 206 provided thereunder, and the process of evaporationends.

The heating member is not limited to the combination of the heating roll204 and the heating plates 205 a and 205 b shown in FIG. 1. The heatingroll alone, which rotates as described above, can be used.Alternatively, one or a plurality of inclined heating plates alone canbe used. Furthermore, a solid cone heater or a cone-shaped heating platecan be used. In this case, when the shape formed by the atomizedparticles of the resin sprayed from the two-fluid nozzle is anapproximately solid cone-shape or hollow cone-shape, and the resinmaterial is sprayed from a point substantially on the central axis ofthe cone surface of the heating member and positioned for apredetermined distance away from the apex, the resin material can beadhered substantially uniformly on the cone surface. Consequently, theevaporation of the resin material can be stabilized. Alternatively,instead of the heating roll, a rotating endless belt that has beenheated can be used. A flat plate is advantageous in that the structurecan be simplified, and the rotating roll or belt is advantageous in thatthe position where the resin material is supplied can be changed overtime, so that the equipment can be small and the temperature of theheating member can be controlled easily.

The liquid resin material preferably is supplied to the heating memberafter being preheated. Preheating reduces the difference in temperaturebetween the resin material and the heating member and reduces thebumping of the resin material. Furthermore, the difference intemperature in a liquid droplet or a liquid film of the resin materialon the heating member can be relatively small, and the resin materialcan be heated substantially uniformly. This prevents the resin materialin the vicinity of the heating member from being heated rapidly andcured by heat. As a result, a resin thin film having a smooth surfaceand no large protrusions can be obtained stably.

The resin material that has been evaporated by the heating roll 204 andthe heating plates 205 a and 205 b moves toward the opening 209 by thedifference in atmospheric pressure between the inside and the outside ofthe resin thin film forming apparatus 200. In this case, the resinmaterial passes between barriers 207 a and 207 b or between barriers 207a and 207 c, and between the barrier 207 a and the opening plate 208.

The barriers 207 a and 207 b, the barriers 207 a and 207 c, the barrier207 a and the opening plate 208 are provided in the following manner.The members of each pair are spaced apart by a predetermined distance,and a part of one member can be opposed to a part of the other member,namely, the members of each pair can have an overlapped portion. Thespacing between barriers can be adjusted in accordance with thethickness of the resin thin film to be formed. In the case where thethickness is small, the spacing can be small, and in the case where thethickness is large, the spacing can be large. When the resin materialpasses between such barriers, variations over time in the amount of theresin material evaporated can be absorbed and the amount of the adheredresin material can be stabilized. Furthermore, since the vapors of theresin material are diffused uniformly in the width direction of thesupporting base, a resin thin film having a uniform thickness in thewidth direction can be obtained.

However, the arrangement of the barriers is not limited to that shown inFIG. 1, and can be changed as appropriate. For example, the distancebetween the opposing barriers, the size of the opposing portions(overlapped portion), the number of the barriers can be changed asappropriate, depending on the type of the resin material or theevaporation conditions or the like. Furthermore, the barriers may becurved plates instead of flat plates.

Furthermore, preferably, the apparatus is designed such that the regionwhere the resin material is ejected from the two-fluid nozzle 230 in theform of atomized particles is not in straight communication with theregion of the supporting base where the resin material is deposited (theopening 209).

In addition, preferably, the apparatus is designed such that the regionsof the heating roll 204 and the heating plates 205 a and 205 b where theresin material is evaporated are not in straight communication with theregion of the supporting base where the resin material is deposited (theopening 209).

These designs can prevent the atomized resin material or the particlesscattered from the heating member as a result of bumping from adheringto the supporting base 110. As a result, defects on the resin thin filmsuch as large protrusions can be prevented so that the resin thin filmcan have a smooth surface. In the apparatus of FIG. 1, the barriers 207a, 207 b and 207 c and the opening 209 are advantageously provided so asto obtain the above-described designs. However, the present invention isnot limited thereto. For example, the resin thin film forming apparatus200 itself is formed so as to have a hook structure so that the sprayedor evaporated resin materials cannot pass straight to the supportingbase.

Furthermore, circumferential walls 203 a and 203 b, the barriers 207 a,207 b and 207 c and the opening plate 208 can be heated to evaporate theresin material that adheres thereto again and to prevent the surfacesthereof from being contaminated.

The evaporated resin material can be charged before adhering to thesupporting base 110. In the apparatus of FIG. 1, a device 211 forirradiating a charged particle beam is provided so as to be directedtoward a region where the resin material passes by. The charged resinparticles are accelerated by electrostatic attraction, and due to themicroscopic electrostatic repulsion during the deposition, they avoidthe portions where charged particles already were deposited. Due to thismechanism, a very smooth resin thin film can be formed. This iseffective especially when a resin material having a large viscosity isused to form a resin thin film having a smooth surface. Instead ofcharging gaseous particles of the resin material, charging the surfaceof the supporting base 110 before the resin material is depositedthereon provides the same effects.

As the device 211 for irradiating charged particle beam, any means canbe used as long as it can charge the resin material particles or thedeposition surface. For example, an electron beam irradiation device, anion source that irradiates an ion beam, a plasma source or the like canbe used The thus formed resin thin film on the supporting base 110 iscured to a desired curing degree by a resin curing device 140, ifnecessary. Examples of the curing methods include electron beamirradiation, curing by heat or the like, in addition to the method usingultraviolet ray irradiation shown in FIG. 1.

The curing method can be selected as appropriate, depending on the resinmaterial used. However, among preferable methods is a method in whichthe resin material is cured by polymerization and/or crosslinking.

The extent of the curing treatment can be changed as appropriate,depending on the use or required characteristics of the resin thin filmto be manufactured. For example, when a resin thin film for use in anelectronic component such as a capacitor is to be manufactured, thecuring treatment is performed preferably until the curing degree reaches50 to 95%, more preferably 50 to 75%. When the curing degree is smallerthan the above described ranges, the resin material can be deformedeasily by an external force or the like in the processes where the resinthin film obtained in the method of the present invention is pressed, oran electronic component including the resin thin film is mounted in acircuit substrate. In addition, metal thin films as electrodes formed onthe resin thin film by vapor deposition or the like can be ruptured orshort-circuited. On the other hand, when the curing degree is largerthan the above-described ranges, the resin thin film may be crackedwhile the supporting base 110 on which the resin thin film is formed istransported or wound, or during the subsequent processes. To determinethe curing degree of the present invention, the ratio of the absorbanceof the C=O groups and the C=C groups (1600 cm⁻¹) is determined with aninfrared spectrophotometer, the ratio of each monomer and the curedproduct is determined, and the curing degree is defined as 1 minus thereduced absorption ratio.

In the process for forming a resin thin film, the vacuum degrees of theupper compartment 150 (the second compartment) and the lower compartment250 (the first compartment) of the vacuum container are changed byvarious factors. For example, the vacuum degree can be changed byexcessive suction of the vacuum pumps 151 and 251, reduction of thevacuum degree due to dispersion of the resin material, or reduction ofthe vacuum degree due to a gas supplied from the gas supply tube 243.When the vacuum degree of the lower compartment 250 is changed, theamount of the gaseous resin material that passes through the opening 209is changed. As a result, the deposition thickness of the formed resinthin film is changed over time. Furthermore, when the difference inatmospheric pressure between the upper compartment 150 and the lowercompartment 250 is changed, and the pressure in the upper compartment150 becomes lower than that in the lower compartment 250, the vapor ofthe resin material enters the upper compartment, so that the resinmaterial adheres to various sliding portions, requiring cleaningoperations, which prevents a continuous operation for a long time.

As means for maintaining the vacuum degrees of the upper compartment 150and the lower compartment 250 and the difference thereof between them,in the apparatus of FIG. 1, the upper compartment 150 and the lowercompartment 250 includes the vacuum pumps 151 and 251 and gas inlettubes 152 and 252 for introducing a gas therein, respectively. The gasinlet tubes 152 and 252 are provided with valves 153 and 253 foradjusting a flow rate so that the amount of the gas introduced can beadjusted.

In the present invention, the resin thin film material is not limitedthereto, and any material can be used as long as it can form a thin filmby being evaporated and deposited, and selected as appropriate dependingon the use of the resin thin film. However, a reactive monomer resin ispreferable. For example, for the resin thin film to be used as anelectronic component material, a material comprising an acrylate resinor a vinyl resin as a main component is preferable. More specifically,polyfunctional (meth)acrylate monomer or a polyfunctional vinyl ethermonomer are preferable. In particular, cyclopentadiene dimethanoldiacrylate, cyclohexane dimethanol divinyl ether monomer or monomerswhose hydrocarbon groups are substituted are preferable. The resin thinfilms formed of these materials have excellent electricalcharacteristics, heat resistance and stability.

The supporting base on which the resin thin film is formed is notlimited to the belt-shaped resin film where Al is vapor-deposited as inthis embodiment. For example, the vapor deposition on the surface is notnecessarily performed. In addition, a metal thin film can be formed byknown methods other than the vapor deposition, such as sputtering, ionplating and metal plating. Furthermore, the metal thin film is notlimited to Al, and other various metals can be used. Furthermore,instead of the belt-shaped supporting base, the supporting base may bein the form of a rotating cylindrical drum, an endless belt, a revolvingdisk or the like.

Embodiment 2

FIG. 4 is a cross-sectional drawing schematically showing an internalstructure of another example of an apparatus used in the method of thepresent invention. The components having the same functions as those inFIG. 1 bear the same reference numerals, and will not be describedfurther.

Embodiment 2 differs from Embodiment 1 in the manner in which the resinmaterial is supplied to the heating roll 204.

In Embodiment 2, a liquid resin material 281 whose flow rate is adjustedto a predetermined flow rate by a flow rate adjusting valve 242 and agas 282 whose flow rate is adjusted to a predetermined flow rate by aflow rate adjusting valve 244 are mixed outside the vacuum container,and the mixture is supplied to a resin thin film forming apparatus 200′through a material supply tube 280 and ejected from a nozzle 270 towarda heating roll 204. Since the inside of the resin thin film formingapparatus 200′ is maintained at a predetermined vacuum, the gas mixedwith the resin material ejected from the nozzle is diffused rapidly.This is accompanied by the resin material being ejected in the form offine atomized liquid droplets.

The ratio of the resin material and the gas in the mixture is requiredto be adjusted in accordance with the properties of the resin materialused (e.g., viscosity) or the flow rate of the resin. The dependence ofthe average particle diameter of the resin sprayed from the nozzle 270,the pressure in the resin thin film forming apparatus 200′, thefilm-forming rate, and the number of defects contained in the resin thinfilm with respect to the gas flow rate when the resin flow rate isconstant is substantially the same as that of FIG. 3, and will not bedescribed further.

As the nozzle 270, a nozzle whose inside is formed from a straight tubeis the most simple in its structure. However, when a spray nozzle isused, the resin can be sprayed in the form of finer particles. As thespray nozzle, any known spray nozzle can be used. The liquid resinmaterial and the gas are mixed, and then the mixture is forced to besupplied to the spray nozzle.

The atomizing means of the resin material according to this embodimenthas a very limited mechanical effect on the resin material, and canminimize changing the nature of the resin material or generating heat.

EMBODIMENT 3

An application example of the method for manufacturing the resin thinfilm of the present invention will be described by taking themanufacturing of a layered product of resin thin films and metal thinfilms as an example.

FIG. 5 is a cross-sectional drawing schematically showing an internalstructure of an example of an apparatus for manufacturing a layeredproduct including resin thin films and metal thin films. The componentshaving the same functions as those in FIGS. 1 to 4 bear the samereference numerals, and will not be described further.

An apparatus 360 for forming a metal thin film (hereinafter, referred toas “metal thin film forming apparatus”) is provided under a can roller302, which rotates in a direction shown by arrow 303 in FIG. 5 with aconstant angular velocity or circumferential velocity. A resin thin filmforming apparatus 200 is provided downstream of the rotation directionof the can roller 302.

Furthermore, in this example, an apparatus 400 for applying a patterningmaterial, which forms margins in the metal thin film (regions where themetal thin film is not formed), is provided upstream of the metal thinfilm forming apparatus 360. Furthermore, an apparatus 370 for removingpatterning material is provided between the metal thin film formingapparatus 360 and the resin thin film forming apparatus 200. A resincuring device 140 and a device 390 for treating a resin surface areprovided between the resin thin film forming apparatus 200 and theapparatus 400 for applying a patterning material. However, theseapparatuses can be provided as appropriate.

These apparatuses are housed in a vacuum container 301. The vacuumcontainer 301 is partitioned into three compartments by partition walls310, 311 and 312, and these compartments are maintained at respectivepredetermined vacuum degrees. In order to maintain each of the vacuumdegrees constant over time, each compartment includes a vacuum pump anda gas supply tube for supplying a gas from the outside. Morespecifically, a vacuum pump 321, a gas supply tube 322 and a flow rateadjusting valve 323 are provided in a compartment (a second compartment)320 including the can roller 302. A vacuum pump 351, a gas supply tube352 and a flow rate adjusting valve 353 are provided in a compartment (athird compartment) 350 including the metal thin film forming apparatus360. A vacuum pump 521, a gas supply tube 522 and a flow rate adjustingvalve 523 are provided in a compartment (a first compartment) 520including the resin thin film forming apparatus 200.

The vacuum degree of each compartment may be set as appropriate.However, for example, the following vacuum degrees are preferable. Thevacuum degree Pv of the compartment (the second compartment) 320including the can roller 302 is set to 3×10⁻³ Torr or less. The vacuumdegree Pa of the compartment (the third compartment) 350 including themetal thin film forming apparatus 360 is set to 1×10⁻⁵ to 1×10⁻⁴ Torr.The vacuum degree Pr of the compartment (the first compartment) 520including the resin thin film forming apparatus 200 is set to 1×10⁻³Torr or less. When Pv is larger than the above-described range, in thecase where plasma discharge is utilized as the device 390 for treating aresin surface, plasma become unstable. When Pa is larger than theabove-described range, the formed metal thin film can be degradedeasily. When Pr is either larger or smaller than the above-describedrange, the scattering of the resin material can be unstable.

Furthermore, it is preferable that the vacuum degrees meet therelationship Pv>Pr>Pa. When the compartment 350 including the metal thinfilm forming apparatus has the lowest pressure, the metal to bedeposited is prevented from entering other compartments. Furthermore,when the compartment 520 including the resin thin film forming apparatus200 has a pressure lower than that of the compartment 320 including thecan roller 302, the resin material is prevented from entering thecompartment including the can roller 302 and adhering to the slidingportions.

The circumferential surface of the can roller 302 is smooth, preferablymirror-finished, and cooled preferably to −20° C. to 40° C., morepreferably −10° C. to 10° C. The rotation velocity can be adjustedfreely, but preferably about 15 to 70 rpm, and the circumferentialvelocity preferably is 20 to 200 m/min. In this embodiment, the canroller 302 that is a cylindrical drum is used as the supporting base,but a belt-shaped supporting base that runs between two or more rolls, arotating disk-shaped supporting base or the like is also possible.

The resin thin film forming apparatus 200 has the same structure as thatdescribed in Embodiment 1. However, this embodiment differs fromEmbodiment 1 in that four heating plates 205 a, 205 b, 205 c, and 205 dare used as the heating members for evaporating the resin material.

Furthermore, in this embodiment, since the metal thin film formingapparatus 360 is provided under the can roller 302, the resin thin filmforming apparatus 200 is provided to the lower left side of the canroller in FIG. 5. Therefore, this embodiment differs from Embodiment 1in that the path of the resin material is bent and a opening plate 208is inclined at a predetermined angle with respect to the horizontaldirection, whereas the opening plate 208 is substantially in parallel tothe horizontal plane in Embodiment 1.

The liquid resin material is adjusted to a predetermined flow rate andsupplied to a two-fluid nozzle 230 in the resin thin film formingapparatus 200 through a resin material supply tube 241. The two-fluidnozzle 230 is the same as that described in Embodiment 1 (see FIG. 2).At the same time, a gas is supplied to the two-fluid nozzle 230 througha gas supply tube 243. As a result, the resin material is ejected in theform of atomized particles toward the heating plate 205 a. The resinmaterial that has adhered to a wide area of the heating plate 205 aforms numerous fine liquid droplets or a thin liquid film, and most ofthem evaporate on the heating plate 205 a. The resin material that hasnot evaporated yet evaporates while moving on the heating plates 205 b,205 c, and 205 d sequentially, and the resin material that still remainswithout being evaporated drops to a cooling cup 206. Evaporated resinmaterial passes between barriers 207 a, 207 b and 207 c and is chargedby a charged particle beam irradiation device 211, so that the resinmaterial adheres onto the circumferential surface of the can roller 302through the opening 209 of the opening plate 208, so that a resin thinfilm is formed.

The formed resin thin film is cured to a desired curing degree by aresin curing device 140.

Then, the resin thin film is subjected to a surface treatment by adevice 390 for treating a resin surface. Examples of the surfacetreatment include a discharge treatment and an ultraviolet rayirradiation treatment in an atmosphere containing oxygen. This treatmentactivates the surface of the resin thin film so as to improve adhesionwith the metal thin film.

The apparatus 400 for applying a patterning material deposits apatterning material on the surface of the resin thin film in apredetermined shape. At the portions where the patterning material hasbeen deposited, no metal thin film is formed, so that these portionsbecome margins (insulating regions). In this embodiment, a predeterminednumber of strips of patterning material of a predetermined width andshape are deposited at predetermined positions in the circumferentialdirection on the surface of the resin thin film formed on the can roller302.

FIG. 6 is a plan view of the apparatus for applying a patterningmaterial used in the manufacturing apparatus of FIG. 5, when viewed fromthe side of the can roller 302.

On the front of the apparatus 400 for applying a patterning material, apredetermined number of pinholes 401 are arranged at predeterminedintervals. The apparatus 400 for applying a patterning material ispositioned in a manner that the pinholes 401 oppose the circumferentialsurface of the can roller 302, which is the deposition surface, and thedirection indicated by arrow 402 matches the travel direction of thedeposition surface. Then, the evaporated patterning material is ejectedfrom the pinholes 401 so as to deposit the patterning material on thedeposition surface, and condensed by cooling, whereby a deposition filmof the patterning material is formed. Consequently, the intervals andthe number of pinholes 401 in FIG. 6 correspond to the intervals and thenumbers of strips of patterning material formed on the surface of theresin thin film.

Contactless applications of the patterning material on the surface ofthe resin prevent deformations of the resin thin film and the metal thinfilm below it, which may cause rupture of the layers or chapping of thesurface.

The patterning material is pre-evaporated, and adjusted to apredetermined flow rate by a flow rate adjusting valve 404 so as to besupplied to the apparatus 400 for applying a patterning material througha line 403. In this case, the line 403 and the apparatus 400 forapplying a patterning material are heated and maintained at apredetermined temperature so that the patterning material is notcondensed.

It is preferable that the deposition position in the width direction ofthe patterning material can be changed in the process of the deposition,where appropriate. For example, the rotating can roller 302 can bedesigned to be moved so that the deposition position of the patterningmaterial is moved for a predetermined amount in a plane parallel to thedeposition surface of the can roller (a plane orthogonal to the normalline of the circumferential surface of the can roller) and in adirection perpendicular to the travel direction of the depositionsurface (direction perpendicular to the travel direction 402 in FIG. 6,namely, the direction of the rotation axis of the can roller 302). Thisdesign provides a layered product including the resin thin films and themetal thin films laminated sequentially where the position of the marginof each layer can be changed. For example, in the case where the layeredproduct is used as an electronic component, this design easily canrealize that the metal thin films sandwiching the resin thin film aremade into electrodes having different electrical potentials.

It is preferable that the patterning material comprises at least one oilof the group consisting of ester oils, glycol oils, fluorocarbon oils,and hydrocarbon oils. It is more preferable that the patterning materialis an ester oil, a glycol oil, or a fluorocarbon oil. It is mostpreferable that the patterning material is a fluorocarbon oil.

The patterning material is required to be able to withstand the thermalload during the formation of the metal thin film, and ensure that nometal thin film is formed at the region where patterning material hasbeen applied. In addition to that, the material is required to beapplied contactless in its gaseous or liquid state on a resin thin filmsurface. Furthermore, the material is required not to clog the pinholesof the apparatus for applying a patterning material. The material may berequired to be compatible with the resin thin film formed with theinventive method and to have a certain wettability. In some cases, thematerial is required to be removable by heat or decomposition in avacuum. Since such special conditions are added, it is preferable thatthe patterning material used in the present invention is an oil that isespecially adapted to these conditions. When materials other than theabove patterning materials are used, the surface of the layered productmay be chapped, pinholes may appear in the resin thin films or the metalthin films, or other problems such as unsteady deposition region of themetal thin films may occur.

The metal thin film forming apparatus 360 forms a metal thin film afterthe desired patterning material is deposited, if necessary. The metalthin film can be formed by vapor deposition, sputtering, ion plating orother well-known methods. For the present invention, however, vapordeposition, especially electron beam vapor deposition, is preferable,because with this method, a film with excellent moisture resistance canbe obtained with high productivity. Possible materials for the metalthin film include aluminum, copper, zinc, nickel, iron, cobalt, silicon,germanium, alloys thereof, their compounds, their oxides, and the oxidesof their compounds. Of these, aluminum is preferable, because of itsadhesiveness and low cost. The metal thin film also can include othercomponents.

In the apparatus of FIG. 5, a movable shielding plate 361 is providedbetween the metal thin film forming apparatus 360 and the can roller 302so that only resin thin films can be formed without forming a metal thinfilm.

It is preferable that residual patterning material is removed after themetal thin film has been formed and before the resin thin film isdeposited. Most of the patterning material that has been deposited withthe apparatus for applying a patterning material is removed by beingagain evaporated when the metal thin film is formed. However, a portionremains even after the formation of the metal thin film, and cancontribute to a number of problems, such as chapping the depositedsurface, causing pinholes (lack of deposition) in the resin thin film orthe metal thin film, or instabilities in the regions where the metalthin film is deposited.

The removal of the patterning material is performed by an apparatus 370for removing patterning material, which is installed between the metalthin film forming apparatus 360 and the resin thin film formingapparatus 200. There is no particular limitation regarding how thepatterning material is removed, and an appropriate method can beselected in accordance with the patterning material type. The patterningmaterial can be removed by heat and/or decomposition, for example.Examples of how the patterning material can be removed by heat includeirradiation of light or use of an electric heater. Devices forirradiation of light can be simple and remove the patterning materialefficiently. Here, “light” includes far infrared and infrared rays.Examples of how the patterning material can be removed by decomposition,on the other hand, include plasma irradiation, ion irradiation, andelectric beam irradiation. For the plasma irradiation, for example oxideplasmas, argon plasmas, or nitrogen plasmas can be used, and amongthese, oxide plasmas are especially preferable in view of decompositionability.

Using the above-described apparatus 300, a layered product comprisingresin thin films and metal thin films can be manufactured on a rotatingsupport base 302.

The obtained layered product can be used as, for example an electroniccomponent such as a conductor for high frequencies, a capacitor and athin film coil, a circuit substrate, a protective film, a functionalfilm or the like.

Hereinafter, an example of a method for manufacturing a chip capacitorwill be described.

A cylindrical multilayered product including the metal thin films andthe resin thin films where margins are formed in predetermined positionsis formed on the circumferential surface of the can roller 302 by theabove-described method. Then, the layered product is cut into 8 segments(by every 45°) in the radial direction and removed, and pressed underheat so as to be formed into a flat shape. FIG. 7 shows a perspectiveview of an example of the outline of the structure of the thus obtainedlayered product base element 600 including the metal thin films and theresin thin films. In FIG. 7, arrow 601 indicates the travel direction ofthe circumferential surface of the can roller 302. The layered productbase element 600 includes a protective layer 604 b, a reinforcementlayer 603 b, an element layer 602, a reinforcing layer 603 a, and aprotective layer 604 a, which are laminated sequentially from the sideof the can roller 302 (the lower side of the sheet of the FIG. 7). Inthe FIG. 7, numeral 606 denotes a metal thin film, numeral 607 denotes aresin thin film, and numeral 608 denotes a margin. FIG. 7 shows aschematic deposition state, and the number of layers deposited aresignificantly smaller than that of an actual capacitor.

The layered product base element is cut at sectional planes 605 a andbrass is sprayed onto the sectional planes to form external electrodes.Furthermore, conductive paste where an alloy of copper, nickel, silveror the like is dispersed in a thermosetting phenol resin is applied tothe surface of the sprayed metal and cured by heat. Then, hot solderdipping is performed on the surface of the resin. Thereafter, thelayered product base element is cut at sectional planes 605 b in FIG. 7and immersed in a silane coupling agent solution so as to coat the outersurface. Thus, a chip capacitor 610 as shown in FIG. 8 is obtained.

Referring to FIG. 8, numerals 611 a and 611 b denote externalelectrodes, and the metal thin films of the element layer 602 areconnected to the external electrodes 611 a and 611 b alternately.Therefore, when an electrical potential difference is applied betweenthe external electrodes 611 a and 611 b, a number of capacitorsincluding the metal thin films of the element layer 602 as electrodesand the resin thin films 607 as dielectrics are connected in parallel,and thus a compact capacitor with a large capacity can be obtained.

The reinforcement layers 603 a and 603 b do not generate capacitance asa capacitor, so that they are not always necessary. However, thereinforcement layers can improve the adhesion strength with the externalelectrodes by connecting the metal thin films of the reinforcementlayers to the external electrodes. Furthermore, the reinforcement layers603 a and 603 b serve to protect the element layer 602 from externalforce or heat together with the protective layers 604 a and 604 b, whichare formed by laminating the resin thin films alone.

In the present invention, there is no particular limitation regardingthe thickness of the resin thin film, but a thickness of not more than 1μm is preferable, a thickness of not more than 0.7 μm is morepreferable, and a thickness of not more than 0.4 μm is most preferable.To full the need for a layered product that is small yet achieves highperformance, it is preferable that the thickness of the resin thin filmof the layered product obtained with the inventive method is small. Forexample, if the layered product obtained with the inventivemanufacturing method is used as a chip capacitor as described above, thecapacitance of the capacitor increases in inverse proportion to thethickness of the resin thin film, which serves as a dielectric layer.

The surface roughness of the resin thin film preferably is not more than0.1 μm, more preferably not more than 0.04 μm, and most preferably notmore than 0.02 μm, although it can be selected as appropriate dependingon the use of the resin thin film. For the metal thin film, a surfaceroughness of not more than 0.1 μm is preferable, a surface roughness ofnot more than 0.04 μm is more preferable, and a surface roughness of notmore than 0.02 μm is most preferable. If the surface roughness islarger, no improvement of characteristics of the resultant layeredproduct can be achieved for various applications, and itscharacteristics become unstable. For example, when applied to a magneticrecording medium, high-density recording becomes difficult, largesurface protrusions cause dropout, and the reliability of the recordingdecreases. When applied to electronic components, high-densityintegration becomes difficult, an electric field is concentrated onlarge surface protrusions, and the resin thin film may be leached or themetal thin film may be burnt.

In this specification, “surface roughness” refers to the ten pointaverage roughness Ra, measured with a contact-type surface meter havinga diamond needle of 10 μm tip diameter and a 10 μg measuring load. Tomeasure the surface roughness of a resin thin film, the needle iscontacted directly with the resin thin film surface, and to measure thesurface roughness of a metal thin film, the needle is contacted directlywith the metal thin film surface. The measurements is required to beperformed while eliminating the influence of all other layered portions(for example, steps due to margins).

In this embodiment, the two-fluid nozzle 230 described in Embodiment 1is used as the atomizing means of the resin material. However, theatomizing means using the nozzle 270 described in Embodiment 2 also canbe used instead.

EXAMPLES

Hereinafter, the present invention will be described more specifically.

Example 1

A resin thin film was formed with the apparatus of FIG. 1 according tothe method shown in Embodiment 1.

An Al vapor-deposited polyester film was used as the supporting base.This polyester film was transported on a can roller 111 of a diameter of500mm whose circumferential surface had been cooled to 5° C. The travelrate was 50 m/min.

The upper compartment 150 in the vacuum container 101 was maintained at5×10⁻⁴ Torr by the vacuum pump 151. The lower compartment 250 includingthe resin thin film forming apparatus 200 was maintained at 2×10⁻⁴ Torrby the vacuum pump 251.

As the resin thin film material, dicyclopentadiene dimethanol diacrylatewas used. The resin material was preheated to 60° C. and supplied to thetwo-fluid nozzle 230 through the resin supply tube 241 at a flow rate of5 cc/min. At the same time, nitrogen was supplied to the two-fluidnozzle 230 through the gas supply tube 243 at a flow rate of 3 cc/min.The resin material ejected from the outlet of the two-fluid nozzle 230in the form of atomized particles was evaporated on the heating roll andthe heating plates, charged with electrostatic charges by the device 211for irradiating a charged particle beam (electron beam irradiationdevice). Then, the resin material was deposited on the supporting base.The amount of the resin material supplied and the pressure of the gaswere adjusted so as to obtain the desired thickness of the resin thinfilm.

Thereafter, the formed resin thin film was cured by the ultraviolet rayirradiation device 140 until the curing degree reached 70%.

In this manner, the resin thin film was formed until the length of thesupporting base reached 10000 m. The thickness of the resin thin filmformed on the supporting base was measured at 10 points by every 1000 m,and the average thickness and the variation (the difference between thelargest value and the smallest value) were obtained. The thickness ofthe resin thin film was measured in the following method. A portion ofthe resin thin film was adhered to a cellophane tape, and peeled andremoved. Then, platinum palladium 5 nm thick was formed on the removedsurface and a step formed by the difference between the presence and theabsence of the resin thin film was measured with an SEM electronmicroscope. The measured step was defined as the thickness of the resinthin film.

The results were that the average thickness of the obtained resin thinfilms was 0.4 μm and the variation of the thickness was 0.02 μm.

Furthermore, when the surface of the formed resin thin film was observedclosely, the surface was uniform and no large protrusions were seen.

Example 2

A resin thin film was formed with the apparatus of FIG. 4 according tothe method shown in Embodiment 2.

The same resin thin film material and gas as those in Example 1wereused. The resin material at a flow rate of 5 cc/min and the gas at aflow rate of 3 cc/min were mixed and ejected in the form of atomizedparticles through the nozzle 270. The amount of the mixture supplied ofthe resin material and the gas were adjusted so as to obtain the desiredthickness of the resin thin film.

The resin thin film was formed in the same manner as in Example 1exceptfor the above-described conditions, and the thickness of the resin thinfilm was measured in the same manner as in Example 1, and the surfacestate was observed.

The results were that the average thickness of the obtained resin thinfilms was 0.4 μm and the variation of the thickness was 0.03 μm.

Furthermore, when the surface of the formed resin thin film was observedclosely, the surface was uniform and no large protrusions were seen.

Comparative Example 1

A resin thin film was formed on a supporting base in the same manner asin Example 1 except that a liquid resin material was atomized with anultrasonic transducer.

FIG. 9 shows a cross-sectional structure of an ultrasonic atomizer used.The ultrasonic atomizer 700 includes a front case 701 and a rear case702, which are coupled into one unit, an atomizing nozzle 710 formed oftitanium, a ceramic piezoelectric element 720, and a balancer 730. Theatomizing nozzle 710, the ceramic piezoelectric element 720, and thebalancer 730 are coupled into one unit as shown in FIG. 9 and held bythe front case 701 and the rear case 702 via elastic supporting members703 and 704. An input terminal 721 that is electrically connected to anelectrode 722 is provided in the rear case 702, and a predetermined highfrequency voltage is applied to the input terminal 721. Thus, thepiezoelectric element 720 vibrates while expanding and contracting inthe horizontal direction of the sheet of FIG. 9 at a predeterminedfrequency. The vibration of the piezoelectric element 720 causes theatomizing nozzle 710 and the balancer 730 to vibrate in the horizontaldirection of the sheet, whereas they have opposite displacementdirections. The mass of the balancer 730 is adjusted so that theamplitude of an atomizing surface 711 at the end of the atomizing nozzle710 becomes largest. The liquid resin material is supplied from a port712 provided at one end of the atomizing nozzle 710. The supplied resinmaterial passes through the atomizing nozzle 710 so as to be ejected inthe form of atomized particles from an opening on the atomizing surface711.

The piezoelectric element was oscillated at 120 kHz, and the resin wassupplied from the port 712 at 5 cc/min, and the resin was atomized atthe atomizing surface 711. Here, no gas is necessary for atomization, sothat the gas supply tube 243 is not connected to the ultrasonic atomizer700. The direction in which the atomized resin was ejected and themethod for evaporating the resin were the same as those in Example 1.

The resin thin film was formed in the same manner as in Example 1exceptfor the above-described conditions, and the thickness of the resin thinfilm was measured in the same manner as in Example 1, and the surfacestate was observed.

The results were that the average thickness of the obtained resin thinfilms was 0.4 μm and the variation of the thickness was 0.15 μm.

Furthermore, when the surface of the formed resin thin film was observedclosely, a large number of large protrusions caused by large particleswere seen, and the film was discontinuous in some parts.

The invention may be embodied in other forms without departing from thespirit or essential characteristics thereof. The embodiments disclosedin this application are to be considered in all respects as illustrativeand not limiting. The scope of the invention is indicated by theappended claims rather than by the foregoing description, and allchanges which come within the meaning and range of equivalency of theclaims are intended to be embraced therein.

INDUSTRIAL APPLICABILITY

The method for manufacturing a resin thin film of the present inventioncan provide a resin thin film having a very small and uniform thicknessand high quality that can be manufactured at low cost. The resin thinfilm obtained by the present invention can be used in a wide range ofapplications for which a conventional resin thin film is used, such as amagnetic recording medium such as a magnetic tape, a wrapping paper, andan electronic component. In particular, the resin thin film obtained bythe present invention having such characteristics as described above canbe used in an electronic component preferably. For example, when theresin thin film is used in a capacitor, especially a chip capacitor, acompact and high capacity capacitor with stable quality can be obtainedinexpensively. Moreover, when it is utilized in the manufacture of anelectronic component such as a chip coil, a noise filter, a chipresister or the like, a compact, high performance and cost-efficientelectronic component can be achieved.

What is claimed is:
 1. A method for manufacturing a resin thin film bydepositing an evaporated resin material on a surface of a supportingbase, comprising: supplying a liquid resin material and a gas to atwo-fluid nozzle by pressure; ejecting the resin material in a form ofatomized particles toward a heating member by the two-fluid nozzle,thereby adhering the resin material to the heating member; andevaporating the resin material on the heating member to obtain theevaporated resin material.
 2. The method according to claim 1, wherein asurface roughness of the resin thin film is not more than 0.1 μm.
 3. Themethod according to claim 1, wherein the gas comprises at least oneselected from the group consisting of nitrogen, oxygen, argon, helium,and neon.
 4. The method according to claim 1, wherein a flow rate of thegas is 10 to 200% of a flow rate of the liquid resin material.
 5. Themethod according to claim 1, wherein the heating member is at least oneselected from the group consisting of a heating plate, a rotatingheating drum, and a rotating heating belt.
 6. The method according toclaim 5, wherein a shape formed by the resin material being ejected inthe form of atomized particles is a fan shape.
 7. The method accordingto claim 1, wherein the heating member is a cone or a cone-shapedheating plate.
 8. The method according to claim 7, wherein a shapeformed by the resin material being ejected in the form of atomizedparticles is a solid cone.
 9. The method according to claim 7, wherein ashape formed by the resin material being ejected in the form of atomizedparticles is a hollow cone.
 10. The method according to claim 1, whereina thickness of the resin thin film is not more than 0.7 μm.
 11. Themethod according to claim 1, wherein the resin material is a reactivemonomer resin.
 12. The method according to claim 1, wherein the liquidresin material is heated before being ejected in the form of atomizedparticles.
 13. The method according to claim 1, wherein a region wherethe resin material is ejected in the form of atomized particles is notin straight communication with a region of the supporting base where theresin material is deposited.
 14. The method according to claim 1,wherein a region of the heating member where the resin material isevaporated is not in straight communication with a region of thesupporting base where the resin material is deposited.
 15. The methodaccording to claim 1, wherein the evaporated resin material reaches adeposition region of the supporting base by passing between barriersthat are provided so as to be apart by a predetermined distance and toform an opposing portion.
 16. The method according to claim 1, whereinthe evaporated resin material is charged.
 17. The method according toclaim 1, wherein the resin thin film is manufactured in a vacuum. 18.The method according to claim 1, wherein the resin thin film is formedon a surface of the supporting base continuously by moving thesupporting base.
 19. The method according to claim 1, wherein the resinthin films are laminated on the supporting base by rotating thesupporting base.
 20. The method according to claim 1, wherein afterbeing deposited, the resin material is cured.
 21. The method accordingto claim 20, wherein the resin material is cured by at least one of theprocesses selected from the group consisting of polymerization andcross-linking.
 22. The method according to claim 20, wherein the resinmaterial is cured until a curing degree of the resin material reaches 50to 95%.
 23. The method according to claim 1, wherein after the resinthin film is formed, a surface of the resin thin film is treated. 24.The method according to claim 23, wherein the surface of the resin thinfilm is treated by at least one of the treatments selected from thegroup consisting of a discharge treatment and an ultraviolet rayirradiation treatment in an atmosphere containing oxygen.
 25. The methodaccording to claim 1, wherein a thickness of the resin thin film is notmore than 1 μm.
 26. The method according to claim 1, wherein after theresin thin film is formed, a metal thin film is laminated thereon. 27.The method according to claim 26, wherein before depositing the metalthin film, a patterning material is deposited on a surface of the resinthin film.
 28. The method according to claim 26, wherein the metal thinfilm is deposited by vapor deposition.
 29. The method according to claim26, wherein the resin thin films and the metal thin films are laminatedalternately on the supporting base by rotating the supporting base. 30.A method for manufacturing a resin thin film by depositing an evaporatedresin material on a surface of a supporting base, comprising: mixing aliquid resin material with a gas; ejecting the resin material in a formof atomized particles toward a heating member that is provided under areduced pressure, thereby adhering the resin material to the heatingmember; and evaporating the resin material on the heating member toobtain the evaporated resin material.
 31. The method according to claim30, wherein after the liquid resin material and the gas are mixed, themixture is forced to be supplied to a spray nozzle, and the resinmaterial is ejected in the form of atomized particles.
 32. The methodaccording to claim 30, wherein the gas comprises at least one selectedfrom the group consisting of nitrogen, oxygen, argon, helium, and neon.33. The method according to claim 30, wherein a flow rate of the gas is10 to 200% of a flow rate of the liquid resin material.
 34. The methodaccording to claim 30, wherein the heating member is at least oneselected from the group consisting of a heating plate, a rotatingheating drum, and a rotating heating belt.
 35. The method according toclaim 30, wherein the heating member is a cone or a cone-shaped heatingplate.
 36. The method according to claim 30, wherein the resin materialis a reactive monomer resin.
 37. The method according to claim 30,wherein the liquid resin material is heated before being ejected in theform of atomized particles.
 38. The method according to claim 30,wherein a region where the resin material is ejected in the form ofatomized particles is not in straight communication with a region of thesupporting base where the resin material is deposited.
 39. The methodaccording to claim 30, wherein a region of the heating member where theresin material is evaporated is not in straight communication with aregion of the supporting base where the resin material is deposited. 40.The method according to claim 30, wherein the evaporated resin materialreaches a deposition region of the supporting base by passing betweenbarriers that are provided so as to be apart by a predetermined distanceand to form an opposing portion.
 41. The method according to claim 30,wherein the evaporated resin material is charged.
 42. The methodaccording to claim 30, wherein the resin thin film is manufactured in avacuum.
 43. The method according to claim 30, wherein the resin thinfilm is formed on a surface of the supporting base continuously bymoving the supporting base.
 44. The method according to claim 30,wherein the resin thin films are laminated on the supporting base byrotating the supporting base.
 45. The method according to claim 30,wherein after being deposited, the resin material is cured.
 46. Themethod according to claim 30, wherein after the resin thin film isformed, a surface of the resin thin film is treated.
 47. The methodaccording to claim 30, wherein a thickness of the resin thin film is notmore than 1 μm.
 48. The method according to claim 30, wherein athickness of the resin thin film is not more than 0.7 μm.
 49. The methodaccording to claim 30, wherein a surface roughness of the resin thinfilm is not more than 0.1 μm.
 50. The method according to claim 30,wherein after the resin thin film is formed, a metal thin film islaminated thereon.